Attempt to create new user in PBA fails with following error:
Login Name can not be used. Please make sure that your Login Name is 5 to 25 characters long and does not contain special characters..
Entered Login Name does not match some of requirements in PBA Login Settings (for 5.4
Home > Configuration Director > Security Manager > Login Settings, for 5.5
Home> System> Settings> Security > Login Settings)
Analyze all the requirements and login that you are trying to create. Login Settings can be updated according to your needs and also Incorrect Login Alert can be modified to specify explicit requirement for Login Name.